Flourishing offshore wind market drives demand for specialised vessels requiring thrusters that deliver precise manoeuvring and DP capability
Strong demand for newbuild service operation vessels (SOVs), wind turbine installation vessels (WTIVs) and crew transfer vessels (CTVs) to support the burgeoning offshore wind market is driving development of new optimised propulsion solutions.
German propulsion manufacturer Schottel, for instance, has unveiled a new Schottel Rudderpropeller (SRP) optimised for dynamically positioned (DP) offshore wind vessels, in particular walk-to-work (W2W) vessels.
Commenting on the new enhanced version of the company’s well known Rudderpropellers, Schottel vice president technology Manfred Heer said: “With the SRP-D, we have significantly increased the DP performance of our Rudderpropellers, resulting in a product that meets the requirements of today’s offshore wind industry.
“Based on the proven principle of the Schottel RudderPropeller, a cost-efficient yet powerful solution has been developed that greatly improves the positional accuracy of a vessel.
“For customers, this means a significant increase in safety and possible operating times on offshore structures, especially in difficult weather conditions.”
The new SRP-D version of the rudder propeller is characterised by reduced propeller acceleration and deceleration times. In combination with a high-speed azimuth steering system with reinforced gear components, the SRP-D enables faster thrust allocation than conventional rudder propellers.
“We have significantly increased the DP performance of our Rudderpropellers”
Thanks to the shorter response times, it is possible to react faster and in a more targeted manner to external forces from wind, weather and currents, thus achieving a higher positional accuracy of the vessel. At the same time, fuel consumption is reduced.
“In addition,” said Schottel, “the SRP-D is marked by its extremely low profile, vertically integrated LE-Drive as well as an additional eight-degree tilt of the lower gearbox.”
The LE-Drive also allows a free choice of motor for vessels with electric, ideally battery-supported energy. Due to its compact design, the LE-Drive opens up more freedom in vessel design. The SRP-D is optionally also available with the drive train in Z-configuration.
Because the gearbox has an eight-degree downward tilt, interaction between the propulsion unit and hull, as well as the propeller flow interaction, are reduced. This results in increased thrust efficiency in DP operation and minimises so-called ‘forbidden zones’.
Azipods for WTIV
In the case of Van Oord’s new WTIV Boreas, Chinese shipbuilder Yantai CIMC Raffles Shipyard has selected ABB to supply an integrated power, automation and propulsion system. When Boreas is delivered in H2 2024, it will be equipped with four Azipod propulsion units with a combined propulsion power of 16 MW.
ABB’s hybrid-electric propulsion system is designed to be future-proof and allow integration of new energy sources once they become available.
The package to be supplied by ABB includes a closed-ring configuration for safer, more efficient and more predictable operations. Through its spinning-reserve and peak-load-shaving capabilities, the energy storage system (ESS) will act as a back-up power source while reducing engine running hours to minimise wear and fuel consumption.
Van Oord will also be able to leverage the ABB Ability remote diagnostic system for continuous remote equipment monitoring, as well as optimised machinery and planned maintenance activities, helping reduce maintenance costs.
An ABB Ability OCTOPUS marine advisory system will enable performance management, predictive maintenance and voyage optimisation.
Boreas will be capable of using methanol as fuel, with the capacity to transport and install the next generation of 25-MW wind turbines.
Propulsion package for Maersk WTIV
Meanwhile, Singaporean shipbuilder Sembcorp Marine has selected Steerprop to supply the complete propulsion package for Maersk Supply Service’s newbuild WTIV.
The Finnish propulsion manufacturer will supply six of Steerprop’s ducted L-drive azimuth propulsors with an output power of 4,500 kW and two 900-kW Steerprop tunnel thrusters for DP, manoeuvring and transit. To support safe and reliable operation, a Steerprop Care condition monitoring package is also part of the contract.
“This collaboration enables the optimal solution for the specific application and operational conditions to be created,” said Steerprop sales manager Olli Knihti.
Maersk Supply Service chief technical officer Frederik Smidth said the thruster package was “central to efficient operations”.
“The thruster package was central to efficient operations”
Earlier this year, Maersk Supply Service was awarded a firm contract by Empire Offshore Wind, the joint venture between Equinor and BP, for installation of the Empire 1 and 2 offshore windfarms in the US and is building the vessel to undertake the contract.
Steel-cutting for the vessel is due to take place Q4 2022. The jacking units, load transfer system and crane will be provided by NOV and the design work was supported by class society ABS. Delivery of the vessel into US waters is expected in 2025.
Aqua Helix, the winner of OSJ’s Offshore Energy Vessel of the Year in 2022, is equipped with two Veth retractable L-Drives and a tunnel thruster, with permanent magnet motors. The revolutionary fast crew supplier (FCS) is the first of a new class from Damen, the FCS 7011. The 74-m FCS is designed to be a fully integrated, offshore crew supply solution capable of not only carrying 120 personnel in comfort over long distances, at speeds of up to 40 knots, across a wide range of weather and sea conditions, but also transferring them safely from the vessel to offshore wind turbines or platform by means of a dedicated Ampelmann S-type gangway.
In one of its latest offshore projects, Veth Propulsion has developed 360-degree shallow-draught bow and stern thrusters for a liftboat application. The Veth Jet 4-K-1300 units, powered by 400-kW electric motors, were installed in NT Flagman, a liftboat purchased by a Turkmenistan owner from the US, and upgraded at Baku Shipyard in Azerbaijan. The units are built in “gondolas” which were specifically designed to make easy /attaching of the units to the vessel’s hull possible, according to a social media post by Veth Propulsion.
